1. Field of the Invention
The present invention is related to the field of pile anchor foundations for supporting tall, heavy and/or large towers or the like which can be subject to high upset forces. More particularly, the present invention is directed to a perimeter pile anchor foundation including a plurality of pile anchors drilled in a circular or generally circular pattern so that adjacent piles overlap and form an arch with compression between the piles to resist soil caving in weak soils.
2. Description of the Related Art
In known pile anchor foundations, the piles extend downwardly from a foundation cap into the underlying soil and are spaced from one another. Such foundations are limited by soil conditions, as weak or wet soils will cave or sluff when, during construction, the ground under the center of the cap is excavated vertically.
Various forms of concrete foundations utilizing operational features of the instant invention have heretofore been disclosed in my earlier U.S. Pat. Nos. 5,586,417, 7,707,797 and 7,618,217 (“the '217 patent”), the disclosures of which are expressly incorporated herein in this application by reference as if fully set forth in their entirety. However, a need exists for a large deep concrete foundation capable of being constructed in cohesionless sands and weak soils with shallow ground water.